Coil winding machine



Dec. 8, 1959 R. HUFFMAN COIL WINDING MACHINE Filed Feb. 17. 1955 FIG. 1

INVENTOR.

ROBERT L. HUFFMAN BY i ATTY.

United States Patent M con. WINDING MACHINE Robert L. Huffman, Palatine,Ill., assignor to General Telephone Laboratories, Incorporated, acorporation of Delaware Application February 17, 1955, Serial No.488,810

3 Claims. (Cl. 242-4) This invention relates to coil winding machinesand more particularly to improvements in machines for winding coils ofwire on toroidal cores.

Toroidal coil winding as practiced today generally employs a hollow wirecarrying ring or shuttle which is disposed to revolve at a constant rateabout its axis and to interlink the core to be wound. A wire guidetravels in a track on one side of the shuttle as the shuttle is rotatedand guides the wire as it is drawn from the shuttle and coiled about thecore. As the wire guide passes through and moves away from the core, alength of Wire is drawn from the shuttle which length of wire forms aloop as the guide again approaches the core. Such a loop in the wiretends to decrease the tension of the wire, thereby loosening the lastcoil of wire placed on the core. Similarly the next coil of wire will beplaced loosely on the core and suddenly be pulled taut. These conditionsmay cause consecutive convolutions of wire to overlap and also may causewire breakage.

The prior art reveals several structures which attempt to prevent theharmful results of this wire loop formation, including A. J. Dowd,2,367,489 and R. M. Conklin, 2,425,511. The above patents disclosestationary and movable pressure pads between whichthe wire in the loopmust be drawn while advancing toward the core.

These structures have reduced the difficulty to some extent, but in manyapplications, fail to overcome the problem sufiiciently to produce thedesired results. Such is the case when fine wire is being wound and alsowhere extreme accuracy is desired in the laying of each convolution.

Difiiculty is also encountered in toroidal winding machines in achievingproper alignment of each convolution with respect to the geometriccenter of the core being .wound. The conventional wire guide is locatedat the side of the shuttle, thus causing the wire to be wound aroundthecore in a plane other than those containing the axis of the core. Theresult is overlapping and unequal size of convolutions.

An object of this invention isthe provision of means in a toroidal coilwinding machine, simple in structure, yet highly eflicient in overcomingthe difficulties caused by the formation of a wire loop during eachconvolution.

Another object of this invention is the provision of means in a toroidalcoil winding machine for assuring that the convolutions of wire areproperly aligned on the core in planes containing the axis of the corethrough the geometric center thereof.

A feature of this invention is the provision of novel means formaintaining uniform tension on the wire during formation of the loop asthe wire is drawn toward and about the core.

Another feature of this invention is the provision of novel guidingmeans to hold the wire in a plane through the geometric center of thecore as each convolution is placed on the core.

In the present invention, a plurality of resilient bristles impinge upona fixed pad and are disposed adjacent one 2,916,220 Patented Dec. 8,1959 another between a point adjacent the core to be wound and a pointadjacent the geometric center of the shuttle. The wire to be wound onthe core slides across the face of the fixed pad on each revolution ofthe wire guide, being retarded in its progress by the ends of theresilient bristles, and thereby a constant tension on the wire ismaintained, sufficient to control the wire in its advancement to thecore and to overcome the harmful effects of the wire loop. Adjacentsolid pads, in general use for this purpose, fail to produce the desiredresult principally because the frictional contact of the wire passingbetween the faces of the solid pads tends to produce a sag in thatportion of the loop which is beneath the pads while applying the desiredtension to the portion of wire above the pads. This is due to the wirefailing to move upward in addition to the lateral movement across thepad. This sag beneath the pads loosens the previous convolution on thecore and may cause skewing on the core and overlapping of adjacentconvolutions. The plurality of bristles in place of a solid pad maintaintension on the entire wire loop since they allow an upward as well asbackward pull thereacross, the bristles bending resiliently in anydirection as required.

Also in the present invention, provision is made to assure properalignment of each convolution of wire on the core in relation to thegeometric center of the core. This is assured by employment of a wireguiding finger which extends through the core to be wound and holds thewire, as it is taken from the wire guide, beneath the inner face of thering where it will be in line with the geometric center of the core.

Other objects and features of the present invention will become apparentto those skilled in the art from the following detailed descriptionthereof when taken in conjunction with the accompanying drawingswherein:

Figure 1 is a fragmentary side elevation of a toroidal coil windingmachine with the brush element remove to show the wire loop passingacross a solid pad.

Figure 2 is a fragmentary plan view, partly in section, showing a brushpad and wire guiding finger in relation to a wire loop being pulled intoplace.

Referring now to the drawings, there is shown a conventional winding andshuttle ring 1 constructed so as to removably interlink a toroidal core2 and interengage drive wheels 3, connected to a suitable driving means(not shown), which wheels are effective to cause the ring 1 to revolvethrough the core 2. The core 2 is supportedv by jaws 4 of theconventional type whichare disposed to rotate the core about itsgeometric center, thereby distributing the convolutions of wire 5uniformly on the core. A conventional wire guide 6 slidablyinterengagesa track formed on the side of the ring 1 so that it willtravel with the ring 1 yet slide on the track under the control of thewire. Lengthsof wire are removed from the ring .1 at the leadingend 7 ofthe wire guide 6 and wound about the core as the ring and wire guiderevolve therethrough. The general construction of the machine is similarto that shown in the Dowd and Conklin patents mentioned earlier.

A wire guiding finger 8 is clamped to a pivoted arm 9 and securedthereon by bolt 10. The finger 8 is formed so as to pass through thecore 2 adjacent and following the contour of the inner face of the ring1 and substantialy in alignment with the center line thereof. One end ofarm 9 encircles and yieldably engages shaft 20, allowing the arm toswing outward for ease of insertion or removal of the core to be wound.Similarly the jaws 4 may be lowered to allow the guiding finger to beswung outward when changing cores and making other adjustments. The endof locking pin 11 fits into a recess in arm 9 and holds arm 9 in placewhen the guiding finger 8 is in proper position for winding.

A stationary plate or pad 12 is mounted on the frame (not shown) insubstantially the position shown in the drawings. A brush 13 is affixedto a tension spring arm 14 which in turn is fixedly held in block 18 byscrews 19. Sufficient tension-is applied by spring 14 to hold thebristles 15 of the brush 13 against the front face 16 of the stationarypad 12. The tension applied may be varied by loosening lock screw 17 andrevolving the block 18 about the shaft 20, which passes therethrough,and again tightening lockscrew 17.

As the winding ring 1 revolves during operation of the machine, the wireguide a, following the counterclockwise path of the ring, guides thewire as it is drawn from the ring. In traveling away from the core 2, alength .of wire will be pulled out through guide 6, which length of wireforms a loop as the guide again returns toward the core. This loopstarts to pass across the face of the stationarypad 12 where itencounters the ends of bristles 15. The bristles maintain a constanttension on the up- .per and lower portions of the loop as the portionengaged by stationary pad and bristles forces its way therebetween. Thelower portion is gradually pulled up and across the padand bristles asthe guide 6 advances toward and through the core 2, and the loop isalmost completely wrapped about the core before the wire finally clearsthe .brush bristles and pad releasing the tension on the wire. By thistime the guide has passed completely through the core and again appliesthe necessary tension to the wire.

As the wire guide 6 passes through the core 2, the wire 5 engages theguiding finger 8 which pushes the wire inwardly behind the inner face ofthe winding ring 1, keeping it in a plane through the center line of thering where it will be aligned with a radius of the core and form itscoils in a plane containing the axis through the geometric center of thecore.

Thus by employment of resilient bristles which consecutively retard theprogress of the wire loop as it is pulled toward the core, a uniformtension on the wire is maintained and a firm, even convolution of wireis laid on the core. Also proper alignment on the core of eachconvolution of wire is assured by employment of the guiding finger whichcontinues to guide the wire into position until the wire is completelywrapped about the core.

Although specific improvements of the invention have been shown anddescribed, it is understood, of course, that various modifications maybe' made therein without departing from the scope of this invention asdefined by the appended claims.

sioning means engaging the back of said brush so as to apply a desiredpressure thereto, means for causing move ment of the loop of wirebetween said stationary member and said bristles during a portion of themovement of the ring as the wire is moved toward said core, a guidingfinger extending through said core in a position adjacent the rear faceof said ring, said finger engaging said wire as it is pulled through thecore and guiding the wire into position on said core.

2. In a toroidal coil winding machine having a shuttle ring disposed tointerlink and revolve in a path substantially through the center of atoroidal core, said ring carrying a supply of wire to be wound on saidcore, a stationary member having one side thereof adjacent the center ofsaid ring and the opposite side thereof adjacent said core, a tensionedbase having a plurality of resilient bristles aflixed thereto at theirroots and having the ends thereof independently contacting a face ofsaid stationary member, each of said bristles, during a portion of themovement of the ring, in cooperation with said stationary memberoffering resilient opposition to the passage of said wire therebetween,to maintain a uniform tension on said wire as it is pulled toward andaround said core, a wire guiding finger projecting through said coreadjacent to and following the contour of the inner face of said ring soas to guide each convolution of wire to a position on said core in aplane containing the axis through the geometric center of said core.

3. In a toroidal coil winding machine having a shuttle ring disposed tointerlink and revolve in a path substantially through the center of atoroidal core, said ring carrying a supply of wire to be wound on saidcore, a stationary member having one side thereof adjacent the center ofsaid ring and the opposite side thereof adjacent said core, a pluralityof resilient bristles having the ends thereof independently contacting aface of said stationary member, means to vary the pressure with whichsaid bristles contact said stationary member, each of said bristles incooperation with said stationary member offering resilient opposition tothe passage of said wire therebetween to maintain a uniform tension onsaid wire during a portion of the movement of the ring as it is pulledtoward and around said core, a wire guiding finger projecting throughsaid core adjacent to and following the contour of the inner face ofsaid ring so as to guide each convolution of wire to a position on saidcore in a plane containing the axis through the geometric center of saidcore.

References Cited in the file of this patent UNITED STATES PATENTS1,305,910 Liddell June 3, 1919 1,851,243 Egli Mar. 29, 1932 2,192,694Quinlan Mar. 5, 1940 2,865,573 Tarara et al Dec. 23, 1958 FOREIGNPATENTS 639,177 Great Britain June 21, 1950

